The present invention relates to a method for recovering active benzo-c-phenanthridine alkaloids from plants containing these compounds.
Sanguinaria canadensis, Linn (family Papvaraceae) is commonly known as Bloodroot, Redroot, Puccoon, Teterwort, etc., and is a perennial herb native to North America. The plant and its juices have been used for various purposes in pre-historical and historical times. The plant has been used, in particular, as a folk remedy. The plant has generally been used whole, either undried (fresh) or dried. The usual procedure is to powder the dried plant and mix it with a carrier. This folk remedy has been tried for such conditions as asthma, bronchitis, dysentery, ringworm and a substantial list of other ailments.
The rhizome of the plant has not been used much in modern times because Sanguinaria is a local irritant which in relatively mild does, up to toxic quantities, produces epigastric burning with vomiting, tormenting thirst, faintness, dimness of vision, vertigo, and alarming prostration. In doses of about one gram it is a violent emetic. The present principal use of Sanguinaria is as a stimulant expectorant in cough syrups and in homeopathic medicine.
An early patent, U.S. Pat. No. 209,331, discloses the use of bloodroot, zinc chloride, and kerosene oil in equal proportions for treating open sores. U.S. Pat. No. 433,257, describes a salve of pulverized bloodroot, armenian bole, powdered rosin, lard, and Stockholm tar for use in the treatment of piles. U.S. Pat. No. 2,344,830, discloses the use of a mixture of zinc chloride, stibnite, and bloodroot to fix and outline diseased tissue for excision by surgery.
More recently, it has been discovered that extracts of Sanguinaria and other plants of the families Papaveracease, Fumariaceae and Berberidaceae such as Macleaya cordata, Corydalis sevctcozii, C. ledebouni, Bocconia frutescens, Argemone mexicanus and Chelidonium majus contain benzo-c-phenanthridine alkaloids, which are believed to have valuable properties in conditioning oral tissue, as well as in preventing and treating gingivitis, periodontitis, and mouth odors. Several patents have disclosed the use of extracts of Sanguinaria for such purposes, notably U.S. Pat. Nos. 4,145,412; 4,376,115; 4,406,881;German Offen. No. 2,907,406; U.K. Pat. No. 2,042,336; Belgian Pat. No. 888,843. These patents describe the use of Sanguinaria extracts as antimicrobial agents as well as mouth treating agents.
The prior art cited above describes a method of extracting active ingredients from Sanguinaria canadensis by extracting cut or ground bloodroot with methanol for at least 24 hours at an elevated temperature, filtering the liquid extract obtained, evaporating the extract to dryness, dissolving the dried residue in chloroform, adjusting the chloroform solution to an acid pH by the addition of hydrochloric acid, filtering the acidified extract, evaporating it to dryness, and dissolving the dried residue in glycerine for mixing with a carrier.